It works slightly better in Chrome although the latest Firefoxes can also handle the moogdoodle. I wouldn’t count on anything else being able to play this demo that uses the experimental Web Audio API for HTML 5 that looks to aiming to bring to the web, all the capabilities of a Commodore 64 SID ;-).

Things you can do (The knobs are unfortunately unmarked, so I had to guess what each knob does):